Electrical Components
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| Illustration 1 | g01123212 |
Brake fuse (1) is located on the instrument panel. This 10 amp fuse receives power when the main power relay is energized.
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| Illustration 2 | g01123217 |
Number one brake relay (2), number two brake relay (3), and number two neutral start relay (4) are located inside the right console. The cover of the right console must be removed for access to these components.
These relays work in conjunction with the parking brake switch. This interaction prevents the operator from releasing the parking brake when the brake is engaged and the propel lever is out of the NEUTRAL position.
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| Illustration 3 | g01123350 |
Backup alarm switch (5) is located at the base of the propel lever. The cover of the right console must be removed for access to this component.
The propel lever controls the backup alarm switch. The switch is closed when the propel lever is in the REVERSE range. The switch is open when the propel lever is in NEUTRAL. The switch is also open when the propel lever is in the FORWARD range.
The brake fuse provides power to the backup alarm switch. The backup alarm sounds when the backup alarm switch is closed.
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| Illustration 4 | g01123406 |
Backup alarm (6) is located at the rear of the machine. The engine compartment cover provides access to this component.
The backup alarm switch controls the backup alarm. This alarm sounds when the backup alarm switch is closed.
Propel Electrical System
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| Illustration 5 | g01123413 |
When the main power relay is closed, power is available at the brake fuse. The 155-PK wire distributes power from the brake fuse to the following locations:
- Contact 1 and contact 3 of the parking brake switch
- Contact 2 of the shift switch
- Contact 30 of the number two neutral start relay
- Contact 1 of the backup alarm switch
With the parking brake switch ON, contacts 3 and 4 are closed. Power transfers into the 419-YL wire. The 419-YL wire delivers power to the parking brake indicator, to the coil of the number two brake relay, to contact 87 of the number two brake relay, and to the coil of the number one brake relay. The parking brake indicator illuminates, and the coils of the relays energize.
When the number one brake relay is energized, the brake solenoid is de-energized, and the parking brake is engaged. The parking brake remains engaged when the parking brake switch is ON. This is regardless of the position of the propel lever.
The parking brake will also remain engaged if the parking brake switch is moved from ON to OFF. This will happen while the propel lever is out of NEUTRAL. When the propel lever is out of NEUTRAL, the neutral start switch is open, and the coil of the number two neutral start relay is de-energized. Power transfers from the 155-PK wire into the C720-BU wire. Power also goes across contacts 30 and 87a of the number two neutral start relay. The C720-BU wire transfers power to contact 30 of the number two brake relay.
When the parking brake switch is moved from ON to OFF, contacts 3 and 4 of the switch open. The 419-YL wire will not have power. Ordinarily, this would cause the coils in the number one and number two brake relays to de-energize. The parking brake would then release. However, since voltage is available at contact 30 of the number two brake relay, power immediately transfers into the 419-YL wire, and the coils of the number one and number two brake relays remain energized. The parking brake indicator will remain illuminated, and the parking brake will remain engaged until the propel lever is moved back to NEUTRAL.
The parking brake will release when the parking brake switch is moved from ON to OFF. This occurs while the propel lever is in NEUTRAL. With the parking brake switch in the OFF position, contacts 1 and 2 are closed. Power transfers through the F765-BR wire to contact 30 of the number one brake relay. Contacts 30 and 87a of the number one brake relay are closed. Power transfers to the coil of the brake solenoid and to the coil of the interlock solenoid. When the brake solenoid is energized, the parking brake is released. When the interlock solenoid is energized, the angle of the swashplate can be changed when the propel lever is moved.
When the shift switch is in the LOW SPEED position, contact 1 and contact 2 of the switch are closed. When the shift switch is in the HIGH SPEED position, contact 2 and contact 3 of the switch are closed.
The 751-GN wire connects contact 3 of the shift switch to the shift solenoid. The shift solenoid is energized when the shift switch is in the HIGH SPEED position.
When the propel lever is in REVERSE, the backup alarm switch is closed. Under this condition, power transfers to the backup alarm, and the alarm sounds.